From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 70C3633D4F0; Thu, 2 Jul 2026 16:46:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783010801; cv=none; b=SW+23JxI7ZneslKmtlF88Hhlp/NjKuzV+bVymx+0beSrJolQDQlUX+7W2qH2flMmq91SQi8Y/uXm9T7g4wkGW8u00SRdYpdyOxwMLbznCBZkhN/KrpuqppJXC4ivcc9j96OioSVNUmgeZNnjbpltzY3VpigSMeEOWlaSXrnD468= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783010801; c=relaxed/simple; bh=iuTg+r2aJb+oRyO/DoJzogbNTbF2ttFca0LZWep7glg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=M+dHySEwnYHM0LPL8ZqBueXdCLeKZY0xLbr5/t1j097DQNOGpkEl7xPKs8rJ8v0UkiGNEfUvfVpXPupEI3HzEyB2HBNm8ElljOky+/JEDHdBJd180c6fV/vdXZZYMU5Pv0m4dI3o0CWfyQuCFz5ytsZZ0dZM5/k8GjDpMCLeYps= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=u+NF5mtb; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="u+NF5mtb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D25291F000E9; Thu, 2 Jul 2026 16:46:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1783010800; bh=UM0pK7gwBmjJaw0CK9vEfDTNkC2XC4JEI2BTkGaTyfw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=u+NF5mtbKT1zcDglTmqIXncfUjP4HdQ2dbt5QyGFTfgLX/4fXPeTwlFfs3WWAFREL p80ZJfP86Cpq6/8W0Cp13pToS/zFvG2lBvHI1gaJVI3n3LiPWsjK+84iXfZ0SxckOP 0mhSCtKnsNK4OYgLuapM4suIKrP+jaeZx5nXcZ0w= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Michael Bommarito , David Howells , Marc Dionne , Jeffrey Altman , Eric Dumazet , "David S. Miller" , Jakub Kicinski , Paolo Abeni , Simon Horman , linux-afs@lists.infradead.org, netdev@vger.kernel.org, stable@kernel.org, Sasha Levin Subject: [PATCH 6.6 040/175] rxrpc: Fix the ACK parser to extract the SACK table for parsing Date: Thu, 2 Jul 2026 18:19:01 +0200 Message-ID: <20260702155116.642120945@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260702155115.766838875@linuxfoundation.org> References: <20260702155115.766838875@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Howells [ Upstream commit 333b6d5bb9f87827ac2639c737bf9613dbae7253 ] Fix modification of the received skbuff in rxrpc_input_soft_acks() and a potential incorrect access of the buffer in a fragmented UDP packet (the packet would probably have to be deliberately pre-generated as fragmented) when AF_RXRPC tries to extract the contents of the SACK table by copying out the contents of the SACK table into a buffer before attempting to parse AF_RXRPC assumes that it can just call skb_condense() and then validly access the SACK table from skb->data and that it will be a flat buffer - but skb_condense() can silently fail to do anything under some circumstances. Note that whilst rxrpc_input_soft_acks() should be able to parse extended ACKs, the rest of AF_RXRPC doesn't currently support that. Further, there's then no need to call skb_condense() in rxrpc_input_ack(), so don't. Fixes: d57a3a151660 ("rxrpc: Save last ACK's SACK table rather than marking txbufs") Reported-by: Michael Bommarito Link: https://lore.kernel.org/r/20260513180907.2061972-1-michael.bommarito@gmail.com Signed-off-by: David Howells cc: Marc Dionne cc: Jeffrey Altman cc: Eric Dumazet cc: "David S. Miller" cc: Jakub Kicinski cc: Paolo Abeni cc: Simon Horman cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org cc: stable@kernel.org Link: https://patch.msgid.link/105362.1780573560@warthog.procyon.org.uk Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/rxrpc/input.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) --- a/net/rxrpc/input.c +++ b/net/rxrpc/input.c @@ -781,7 +781,18 @@ static void rxrpc_input_soft_acks(struct struct rxrpc_skb_priv *sp = rxrpc_skb(skb); unsigned int i, old_nacks = 0; rxrpc_seq_t lowest_nak = seq + sp->nr_acks; - u8 *acks = skb->data + sizeof(struct rxrpc_wire_header) + sizeof(struct rxrpc_ackpacket); + u8 sack[256] __aligned(sizeof(unsigned long)); + u8 *acks = sack; + + /* Extract the SACK table into a flat buffer rather than accessing it + * directly through skb->data, which is not guaranteed to be linear for + * a fragmented packet (skb_condense() can silently fail to linearise + * it). + */ + if (skb_copy_bits(skb, + sizeof(struct rxrpc_wire_header) + sizeof(struct rxrpc_ackpacket), + sack, umin(sp->nr_acks, sizeof(sack))) < 0) + return; for (i = 0; i < sp->nr_acks; i++) { if (acks[i] == RXRPC_ACK_TYPE_ACK) {